testsuite: Add broken tests for #19244

3 files changed, 58 insertions, 0 deletions

diff --git a/testsuite/tests/backpack/should_compile/T19244a.bkp b/testsuite/tests/backpack/should_compile/T19244a.bkp
new file mode 100644
index 0000000000..6897378240
--- /dev/null
+++ b/testsuite/tests/backpack/should_compile/T19244a.bkp
@@ -0,0 +1,43 @@
+{-# LANGUAGE PolyKinds #-}
+{-# LANGUAGE ConstraintKinds #-}
+{-# LANGUAGE TypeSynonymInstances #-}
+{-# LANGUAGE FlexibleInstances #-}
+{-# LANGUAGE RoleAnnotations #-}
+unit user where
+    signature Map where
+        type role Map nominal representational
+        data Map k a
+        class Key k
+        instance Key String
+        empty  :: Map k a
+        lookup :: Key k => k -> Map k a -> Maybe a
+        insert :: Key k => k -> a -> Map k a -> Map k a
+    module User where
+        import Prelude hiding (lookup)
+        import Map
+        x = lookup "foo" (insert "foo" True empty)
+unit ordmap where
+    module Map(module Data.Map, Key) where
+        import Data.Map
+        type Key = Ord
+unit eqmap where
+    module Map where
+        import Prelude hiding (lookup)
+        import qualified Prelude
+        type role Map nominal representational
+        newtype Map k a = Assoc [(k, a)]
+        type Key = Eq
+        -- Ugh, need the type signatures, otherwise the quantifiers
+        -- are put in the wrong order.  See #12441
+        empty :: Map k a
+        empty = Assoc []
+        lookup :: Eq k => k -> Map k a -> Maybe a
+        lookup k (Assoc xs) = Prelude.lookup k xs
+        -- Need to insert redundant constraint to make it work...
+        insert :: Eq k => k -> a -> Map k a -> Map k a
+        insert k v (Assoc xs) = Assoc ((k,v):xs)
+unit main where
+    dependency user[Map=ordmap:Map] (User as User.Ord)
+    dependency user[Map=eqmap:Map] (User as User.Eq)
+
+
diff --git a/testsuite/tests/backpack/should_compile/T19244b.bkp b/testsuite/tests/backpack/should_compile/T19244b.bkp
new file mode 100644
index 0000000000..152a7d6449
--- /dev/null
+++ b/testsuite/tests/backpack/should_compile/T19244b.bkp
@@ -0,0 +1,13 @@
+{-# LANGUAGE Haskell2010 #-}
+{-# LANGUAGE PolyKinds #-}
+{-# LANGUAGE ConstraintKinds #-}
+{-# LANGUAGE FlexibleInstances #-}
+unit user where
+    signature Map where
+        class Key k
+        instance Key String
+    module User where import Map
+unit ordmap where
+    module Map(Key) where type Key = Ord
+unit main where
+    dependency user[Map=ordmap:Map] (User as User.Ord)
diff --git a/testsuite/tests/backpack/should_compile/all.T b/testsuite/tests/backpack/should_compile/all.T
index ac8c2a7ed8..a747a461a4 100644
--- a/testsuite/tests/backpack/should_compile/all.T
+++ b/testsuite/tests/backpack/should_compile/all.T
@@ -58,3 +58,5 @@ test('T13149', expect_broken(13149), backpack_compile, [''])
 test('T13214', normal, backpack_compile, [''])
 test('T13250', normal, backpack_compile, [''])
 test('T13323', normal, backpack_compile, [''])
+test('T19244a', expect_broken(19244), backpack_compile, [''])
+test('T19244b', expect_broken(19244), backpack_compile, [''])